Steel making processes employing either a blast furnace, basic oxygen furnace or an electric arc furnace typically use large amounts of refined ore and recycle steel scrap. The waste produced during the refining and melting includes fines and dust containing oxides of iron as well as other materials.
Furnace dust containing high levels of lead, zinc and cadmium oxides has been declared hazardous and must be collected and reprocessed in order to protect the environment. Because of the presence of lead, zinc and cadmium oxides, as well as other materials, attempts to reclaim the iron oxides directly for reuse have not proved to be practical. Various alternatives to the direct recovery of the iron oxides have been proposed. One such proposal is to agglomerate moist dust to form briquettes or pellets and then subject the briquettes to a very high temperature to reduce the iron oxides so that the metal can be recovered for the steel making process. In some situations, raw ore containing metal oxides such as titanium or zinc are subjected to a reduction process to recover various constituents of the ore.